Unified color control method for multi-color light

ABSTRACT

A unified color control method for a multi-color light, including the following control steps: S1: setting unified color control system and color implementation system for different light sources; S2: inputting a target color parameter, and calculating a target color chromaticity coordinate (xt,yt) by the color control system according to the target color parameter: S3: calculating a primary-color duty ratio Di of corrected colors by the color implementation system using a linear programming equation according to the target color chromaticity coordinate (xt,yt), and a chromaticity coordinate value (xi,yi) and a maximum brightness value Yi of each primary color for each light source under a maximum duty ratio, in which i represents an i-th primary color; and S4: updating colors by the light sources according to the primary-color duty ratio Di of corrected colors in step S3.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of International ApplicationNo. PCT/CN2021/074298, filed on Jan. 29, 2021, which claims prioritiesfrom Chinese Patent Application No. 202010983042.7 filed on Sep. 18,2020, all of which are hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to the technical field of color lights andmore particularly to a unified color control method for a multi-colorlight.

BACKGROUND

Single-color or three primary-color LED light sources often fail to meetperformance requirements of lighting on the stage in terms of brightnessand color gamut, so that light sources such as based on four primarycolors, five primary colors, six primary colors, and the like aregradually manufactured. However, there tends to be differences in lightcolor and brightness between light sources, which not only leads tochromatic aberrations and brightness differences, but also causesdifficulty in unified control color and severely degrades userexperiences.

SUMMARY

The present invention thus provides a unified color control method for amulti-color light, which can uniformly control color and modify colorcontrol for different light sources, effectively eliminate differencesbetween different light sources, unify corrected colors, reduce colorhopping, and improve user experiences.

According to the present invention, the unified color control method fora multi-color light, including the following control steps:

S1: setting unified color control system and color implementation systemfor different light sources;

S2: inputting a target color parameter, and calculating a target colorchromaticity coordinate (x_(t),y_(t)) by the color control systemaccording to the target color parameter;

S3: calculating a primary-color duty ratio D_(i) of corrected colors bythe color implementation system using a linear programming equationaccording to the target color chromaticity coordinate (x_(t),y_(t)), anda chromaticity coordinate value (x_(i),y_(i)) and a maximum brightnessvalue Y_(i) of each primary color for each light source under a maximumduty ratio, in which i represents an i-th primary color; and

S4: updating colors by the light sources according to the primary-colorduty ratio D_(i) of corrected colors in step S3.

By providing a unified color control system for a plurality of lightsources with the number of primary colors greater than or equal tothree, the unified color control method for a multi-color lightaccording to the present technical solution can achieve unified targetcolors after correction and finally presents consistent correctedcolors. When the same color control system is used for light sources ofdifferent models of lights, the color control system can correctproperties for each light source separately when the same target colorparameter is input, thereby avoiding mutual differences between lightsources, achieving color synchronization between lights of the samemodel and different models, and achieving unified light output ofcorrected colors.

Setting a color control system in step S1 comprises the following steps:

S11: measuring respective color gamuts of different light sources toobtain a common color gamut;

S12: selecting virtual primary-color chromaticity coordinates (x₁,y₁),(x₂,y₂) . . . (x_(n),y_(n)) and a virtual white point chromaticitycoordinate (x_(w),y_(w)) of the color control system within the commoncolor gamut; and

S13: calculating a color conversion matrix

$\quad\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & \; & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & \; & \left( Z_{n} \right)\end{bmatrix}$for converting the target color parameter to the target colorchromaticity coordinate (x_(t),y_(t)) according to the virtualprimary-color chromaticity coordinates (x₁,y₁), (x₂,y₂) . . .(x_(n),y_(n)) and the virtual white point chromaticity coordinate(x_(w),y_(w)).

The respective color gamuts of the light sources needs to be measuredone by one or model by model or batch by batch to obtain as much colorgamut data for each one/each model/each batch of light sources aspossible. Considering that even an actual luminous efficiency of thesame model/batch of light sources is distinct, it is preferable toperform measurement one by one to precisely unify light emission colorsof all light sources.

Selecting virtual primary-color chromaticity coordinates (x_(i),y₁),(x₂,y₂) . . . (x_(n),y_(n)) and a virtual white point chromaticitycoordinate (x_(w),y_(w)) of the color control system within the commoncolor gamut can ensure that different light sources after correctionhave a common color display range, and avoids that some colors can onlybe displayed by a part of light sources.

Since the input target color parameter is generally an RGB color valuein which the lowest value of each color is 0 and the highest value is255, the target color parameter is first converted to a target colorprimary-color duty ratio within a multi-color light, which does notfacilitate the color implementation system to convert and calculate theprimary-color duty ratio of corrected colors. Therefore, the colorconversion matrix

$\quad\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & \; & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & \; & \left( Z_{n} \right)\end{bmatrix}$can be used to quickly convert the target color primary-color duty ratioto the target color chromaticity coordinate (x_(t),y_(t)) andfacilitates conversion with the corrected colors.

Step S11 is specifically as follows: measuring respective color gamutsof different light sources and recording into a chromaticity diagram toform a plurality of first convex polygons, a maximum value of eachprimary color forms a vertex when recording a color gamut of each lightsource in the chromaticity diagram, connecting lines of the plurality ofvertices forms the first convex polygon, and an intersection of all thefirst convex polygons is the common color gamut. The common color gamutis a common color interval for all the light sources, the respectivecolor gamuts of different light sources can be measured and recordedautomatically using a device, and the common color gamut can be visuallyobtained using geometric construction within the chromaticity diagramand also can be automatically obtained using software according to themeasured respective color gamuts of different light sources.

Step S12 is specifically as follows: making a second convex polygon witha number n as the number of edges within the common color gamutaccording to the number n of primary colors required to be virtual; inwhich n≥3; and setting vertex coordinates of the second convex polygonas (x₁,y₁), (x₂,y₂) . . . (x_(n),y_(n)) respectively, taking the vertexcoordinates of the second convex polygon as the virtual primary-colorchromaticity coordinates of the color control system, and taking one ofthe coordinate points in the second convex polygon as the virtual whitepoint chromaticity coordinate (x_(w),y_(w)). The number n of primarycolors required to be virtual is a controlled variable number of lightsources. The vertices of the second convex polygon can be freelyselected as desired so long as the vertices are within the common colorgamut. A larger area of the second convex polygon results in a widercolor display range of light sources.

Step S13 comprises the following steps:

S13-1: calculating a primary-color tristimulus value

$\quad\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}$and a white-point tristimulus value

$\quad\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$that correspond to the virtual primary-color chromaticity coordinates(x_(i),y_(i)), (x₂,y₂) . . . (x_(n),y_(n)) and the virtual white pointchromaticity coordinate (x_(w),y_(w)) respectively when the brightnessis maximum in step S12, a brightness value at this time is 1, i.e., thevalues of Y₁, Y₂ . . . Y_(n) and Y_(w) are all 1; and

S13-2: calculating tristimulus values corresponding to each primarycolor unit using Grassmann's Law based on the primary-color tristimulusvalue

$\quad\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}$and the white-point tristimulus value

$\quad\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$in step S13-1, a tristimulus value corresponding to each primary colorunit is a color conversion matrix

$\quad{\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & \; & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & \; & \left( Z_{n} \right)\end{bmatrix},}$thereby solving values of the color conversion matrix

$\quad\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & \; & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & \; & \left( Z_{n} \right)\end{bmatrix}$and converting the target color parameter to the target colorchromaticity coordinate (x_(t),y_(t)) using the color conversion matrix

$\quad{\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & \; & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & \; & \left( Z_{n} \right)\end{bmatrix}.}$

Step S13-1 is specifically as follows:

calculating a primary-color tristimulus value

$\quad\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}$and a white-point tristimulus value

$\quad\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$that correspond to the virtual primary-color chromaticity coordinates(x₁,y₁), (x₂,y₂) . . . (x_(n),y_(n)) and the virtual white pointchromaticity coordinate (x_(w),y_(w)) respectively when the brightnessis maximum and a Y value of the tristimulus value is 1 according to aconversion formula

$\quad\left\{ \begin{matrix}{X = \frac{x}{y}} \\{Z = \frac{1 - x - y}{y}}\end{matrix} \right.$between a chromaticity coordinate value and a tristimulus value, inwhich, the values of Y₁, Y₂ . . . Y_(n) and Y_(w) are all 1;

obtaining a conversion formula

$\left\{ {\begin{matrix}{X = \frac{x}{y}} \\{Z = \frac{1 - x - y}{y}}\end{matrix}\quad} \right.$between a chromaticity coordinate value and a tristimulus value byconversion when the Y value is 1 due to the conversion formula

$\left\{ {\begin{matrix}{x = \frac{X}{X + Y + Z}} \\{y = \frac{Y}{X + Y + Z}}\end{matrix}\quad} \right.$between a tristimulus value and a chromaticity coordinate value; and

substituting the virtual primary-color chromaticity coordinates (x₁,y₁),(x₂,y₂) . . . (x_(n),y_(n)) and the virtual white point chromaticitycoordinate (x_(w),y_(w)) into this conversion formula to obtaincorresponding primary-color tristimulus value

$\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \cdots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}\quad$and white-point tristimulus value

$\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}\quad$when the brightness is maximum, in which, for ease of description, the Yvalue is still represented by a character without being converted to avalue 1.

Step S13-2 is specifically as follows:

S13-2-1: setting duty ratios of each of the primary colors in a mixedcolor of the color control system respectively as P₁, P₂, . . . P_(n),in which 0≤P₁, P₂ . . . P_(n)≤1, the color may be any color locatedwithin the common color gamut, and a tristimulus value of the mixedcolor according to Grassmann's Law is

$\begin{matrix}{\begin{bmatrix}X \\Y \\Z\end{bmatrix}{\quad{= {\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & \; & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \cdots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & \; & \left( Z_{n} \right)\end{bmatrix}{\quad{{\cdot \begin{bmatrix}P_{1} \\P_{2} \\\vdots \\P_{n}\end{bmatrix}},}}}}}} & \end{matrix}$i.e., the tristimulus value

$\begin{bmatrix}X \\Y \\Z\end{bmatrix}\quad$of the mixed color equals to a product of the tristimulus value

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & \; & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \cdots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & \; & \left( Z_{n} \right)\end{bmatrix}\quad$corresponding to each primary color unit and duty ratios P₁, P₂, . . .P_(n) of each of the primary colors in the mixed color;

S13-2-2: setting a linear coefficient between the tristimulus value

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & \; & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \cdots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & \; & \left( Z_{n} \right)\end{bmatrix}\quad$for each primary color unit and the tristimulus value

$\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \cdots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}\quad$of the virtual primary-color chromaticity coordinates (x₁,y₁), (x₂,y₂) .. . (x_(n),y_(n)) when the brightness is maximum as

$\begin{bmatrix}K_{1} \\K_{2} \\\vdots \\K_{n}\end{bmatrix}\quad$since tristimulus values change linearly, then the tristimulus value foreach primary color unit becomes

$\begin{matrix}{\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & \; & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \cdots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & \; & \left( Z_{n} \right)\end{bmatrix}{\quad{= {\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \cdots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}{\quad{{\cdot \begin{bmatrix}K_{1} \\K_{2} \\\vdots \\K_{n}\end{bmatrix}}{\quad;}}}}}}} & \end{matrix}$and

combining Formula {circle around (1)} and Formula {circle around (2)} toobtain the tristimulus value of the mixed color as

$\begin{bmatrix}X \\Y \\Z\end{bmatrix}{\quad{= {\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \cdots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}{\quad{{\cdot \begin{bmatrix}P_{1} \\P_{2} \\\vdots \\P_{n}\end{bmatrix} \cdot \begin{bmatrix}K_{1} \\K_{2} \\\vdots \\K_{n}\end{bmatrix}}{\quad;}}}}}}$

S13-2-3: the white point tristimulus value, corresponding to the virtualwhite point chromaticity coordinate (x_(w),y_(w)) when the brightness ismaximum, is known as

$\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}\quad$since a primary-color duty ratio when the brightness is maximum is aninverse matrix of

$\begin{matrix}{{\begin{bmatrix}P_{1} \\P_{2} \\\vdots \\P_{n}\end{bmatrix} = \begin{bmatrix}1 \\1 \\\vdots \\1\end{bmatrix}},{{{then}\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}}{\quad{= {\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \cdots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}{\quad{{\cdot \begin{bmatrix}K_{1} \\K_{2} \\\vdots \\K_{n}\end{bmatrix}},{{{and}\begin{bmatrix}K_{1} \\K_{2} \\\vdots \\K_{n}\end{bmatrix}}{\quad{= {\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \cdots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}^{- 1} \cdot {\quad{\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}{\quad{,{{in}\mspace{14mu}{{which}\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \cdots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}}^{- 1}\quad}}}}}}}}}}}}}}}} & \end{matrix}$is an inverse matrix of

$\begin{bmatrix}X_{1} & X_{2} & \; & X_{n} \\Y_{1} & Y_{2} & \cdots & Y_{n} \\Z_{1} & Z_{2} & \; & Z_{n}\end{bmatrix}{\quad;}$and

S13-2-4: substituting values of the linear coefficient

$\begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}$calculated in Equation {circle around (3)} into Equation {circle around(2)} to obtain the values of the color conversion matrix

${\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}{as}}{{\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix} \cdot \begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1} \cdot \begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}},}$in which

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$is the primary-color tristimulus value corresponding to the virtualprimary-color chromaticity coordinates (x₁,y₁), (x₂,y₂) . . .(x_(n),y_(n)) when the brightness is maximum,

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1}$is the inverse matrix of

${\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix},\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}}$is the white point tristimulus value corresponding to the virtual whitepoint chromaticity coordinate (x_(w),y_(w)) when the brightness ismaximum, and sequential calculations can result in the values of thecolor conversion matrix

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix},$i.e., the tristimulus values corresponding to each of the primary colorunits. It should be noted that

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}{{and}\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}}^{- 1}$in array operations cannot be simplified and combined, both of which arenot reciprocal to each other, as will be appreciated by those skilled inthe art.

Step S2 comprises the following steps:

S21: calculating a tristimulus value

$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix}$of the target color by the color control system using the colorconversion matrix according to the input target color parameter; and

S22: converting the target color tristimulus value

$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix}$by the color control system to the target color chromaticity coordinate(x_(t),y_(t)) according to the conversion formula

$\left\{ \begin{matrix}{x = \frac{X}{X + Y + Z}} \\{y = \frac{Y}{X + Y + Z}}\end{matrix} \right.$between a chromaticity coordinate value and a tristimulus value, inwhich (x,y) represents the chromaticity coordinate, and

$\begin{bmatrix}X \\Y \\Z\end{bmatrix}$represents the tristimulus value.

The target color parameter is firstly converted to the target colortristimulus value

$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix},$which facilitates converting the target color tristimulus value

$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix}$to the target color chromaticity coordinate value (x_(t),y_(t))according to the conversion formula between the tristimulus value andthe chromaticity coordinate value, thereby ultimately converting thetarget color chromaticity coordinate value by the color implementationsystem to the primary-color duty ratio D_(i) of corrected colors.

Setting color implementation in step S1 comprises: measuring thechromaticity coordinate values (x_(i),y_(i)) and a maximum brightnessvalue Y_(i) of each of the primary colors of different light sourcesunder a maximum duty ratio, in which i represents an i-th primary color,and storing measurement values into corresponding lights. Similar tomeasuring respective color gamuts of light sources, both thechromaticity coordinate values (x_(i),y_(i)) and a maximum brightnessvalue Y_(i) of each of the primary colors of different light sourcesunder a maximum duty ratio are measured one by one, model by model, orbatch by batch, both of which are measured in the same manner.

Step S3 is specifically as follows:

substituting the target color chromaticity coordinate value(x_(t),y_(t)) and the chromaticity coordinate value (x_(i),y_(i)) andthe maximum brightness value Y_(i) of each of the primary colors ofcorresponding light sources under a maximum duty ratio into a conversionformula between a tristimulus value and a chromaticity coordinate valueto

obtain

${x_{t} = {\frac{X_{t}}{X_{t} + Y_{t} + Z_{t}} = {\frac{\sum\limits_{t = 1}^{n}{\left\lbrack {x_{t^{*}}\left( {X_{t} + Y_{t} + Z_{t}} \right)} \right\rbrack*D_{t}}}{\sum\limits_{t = 1}^{n}{\left( {X_{t} + Y_{t} + Z_{t}} \right)*D_{t}}} = {\frac{\sum\limits_{t = 1}^{n}{\frac{n_{t}*Y_{t}}{y_{t}}*D_{t}}}{\sum\limits_{t = 1}^{n}{\frac{Y_{t}}{y_{t}}*D_{t}}}{and}}}}}{{y_{t} = {\frac{Y_{t}}{X_{t} + Y_{t} + Z_{t}} = {\frac{\sum\limits_{t = 1}^{n}{\left\lbrack {y_{t^{*}}\left( {X_{t} + Y_{t} + Z_{t}} \right)} \right\rbrack*D_{t}}}{\sum\limits_{t = 1}^{n}{\left( {X_{t} + Y_{t} + Z_{t}} \right)*D_{t}}} = \frac{\sum\limits_{t = 1}^{n}{\frac{y_{t}*Y_{t}}{y_{t}}*D_{t}}}{\sum\limits_{t = 1}^{n}{\frac{Y_{t}}{y_{t}}*D_{t}}}}}},}$and obtain the following after simplification:

$\begin{matrix}{{{\sum\limits_{t = 1}^{n}{\frac{Y_{t}*\left( {x_{t} - x_{t}} \right)}{y_{t}}*D_{i}}} = 0};} & \end{matrix}$ $\begin{matrix}{{{\sum\limits_{t = 1}^{n}{\frac{Y_{t}*\left( {y_{t} - y_{t}} \right)}{y_{t}}*D_{i}}} = 0};} & \end{matrix}$

in which 0≤D_(i)≤1, n is the number of primary colors, i represents ani-th primary color, and the primary-color duty ratio D_(i) of correctedcolors is solved using linear programming in combination with Equation{circle around (4)} and Equation {circle around (5)}, and

Setting an objective function as maximized target color brightness, thenmax Z=Σ_(i=1) ^(n)Y_(i)*D_(t) {circle around (6)};

in which max Z represents the maximum brightness, Equation {circlearound (4)}, Equation {circle around (5)} and Equation {circle around(6)} are solved using linear programming to obtain the primary-colorduty ratio D_(i) of corrected colors.

BRIEF DESCRIPTION OF THE DRAWINGS

The FIGURE is a schematic diagram according to an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE EMBODIMENT

The drawings are for illustrative purposes only and are not to beconstrued as limiting the present invention. Some components in thedrawings may be omitted, enlarged, or reduced for better illustratingthe following embodiments, and sizes of these components do notrepresent sizes of actual products. For those skilled in the art, itwill be understood that some known structures and descriptions thereofin the drawings may be omitted.

As shown in the FIGURE, a unified color control method for a multi-colorlight is provided according to an embodiment, including the followingcontrol steps:

S1: setting unified color control system and color implementation systemfor different light sources;

S2: inputting a target color parameter, and calculating a target colorchromaticity coordinate (x_(t),y_(t)) by the color control systemaccording to the target color parameter;

S3: calculating a primary-color duty ratio D_(i) of corrected colors bythe color implementation system using a linear programming equationaccording to the target color chromaticity coordinate (x_(t),y_(t)), anda chromaticity coordinate value (x_(i),y_(i)) and a maximum brightnessvalue Y_(i) of each primary color for each light source under a maximumduty ratio, in which i represents an i-th primary color; and

S4: updating colors by the light sources according to the primary-colorduty ratio D_(i) of the corrected colors in step S3.

By providing a unified color control system for a plurality of lightsources with the number of primary colors greater than or equal tothree, the unified color control method for a multi-color lightaccording to the present embodiment can achieve unified target colorsafter correction and finally presents consistent corrected colors. Whenthe same color control system is used for light sources of differentmodels of lights, the color control system can correct properties foreach light source separately once the same target color parameter isinput, thereby avoiding mutual differences between light sources,achieving color synchronization between lights of the same model anddifferent models, and achieving unified light output of correctedcolors.

In a preferred embodiment of the present invention, setting a colorcontrol system in step S1 comprises the following steps:

S11: measuring respective color gamuts of different light sources toobtain a common color gamut;

S12: selecting virtual primary-color chromaticity coordinates (x₁,y₁),(x₂,y₂) . . . (x_(n),y_(n)) and a virtual white point chromaticitycoordinate (x_(w),y_(w)) of the color control system within the commoncolor gamut; and

S13: calculating a color conversion matrix

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}$for converting the target color parameter to the target colorchromaticity coordinate (x_(t),y_(t)) according to the virtualprimary-color chromaticity coordinates (x₁,y₁), (x₂,y₂) . . .(x_(n),y_(n)) and the virtual white point chromaticity coordinate(x_(w),y_(w)).

The respective color gamuts of the light sources needs to be measuredone by one or model by model or batch by batch to obtain as much colorgamut data for each one/each model/each batch of light sources aspossible. Considering that even an actual luminous efficiency of thesame model/batch of light sources is distinct, it is preferable toperform measurement one by one to precisely unify light emission colorsof all light sources.

Preferably, in the present embodiment, the respective color gamuts ofthe light sources are measured one by one to improve color consistencyof multi-color lights as much as possible.

Selecting virtual primary-color chromaticity coordinates (x₁,y₁),(x₂,y₂) . . . (x_(n),y_(n)) and a virtual white point chromaticitycoordinate (x_(w),y_(w)) of the color control system within the commoncolor gamut can ensure that different light sources after correctionhave a common color display range, and avoids that some colors can onlybe displayed by a part of light sources.

Since the input target color parameter is generally an RGB color valuein which the lowest value of each color is 0 and the highest value is255, the target color parameter is firstly converted to a target colorprimary-color duty ratio within a multi-color light, which does notfacilitate the color implementation system to convert and calculate theprimary-color duty ratio of corrected colors. Therefore, the colorconversion matrix

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}$can be used to quickly convert the target color primary-color duty ratioto the target color chromaticity coordinate (x_(t),y_(t)) andfacilitates conversion with the corrected colors.

In a preferred embodiment of the present invention, step S11 comprisesthe steps of measuring respective color gamuts of different lightsources and recording into a chromaticity diagram to form a plurality offirst convex polygons, in which a maximum value of each primary colorforms a vertex when recording a color gamut of each light source in thechromaticity diagram, connecting lines of the plurality of verticesforms the first convex polygon, and an intersection of all the firstconvex polygons is the common color gamut. The common color gamut is acommon color interval for all the light sources. The respective colorgamuts of different light sources can be measured and recordedautomatically using a device, and the common color gamut can be visuallyobtained using geometric construction within the chromaticity diagramand can also be automatically obtained using software according to themeasured respective color gamuts of different light sources.

In a preferred embodiment of the present invention, step S12 comprisesthe steps of making a second convex polygon with a number n as thenumber of edges within the common color gamut according to the number nof primary colors required to be virtual, in which n≥3; and settingvertex coordinates of the second convex polygon as (x₁,y₁), (x₂,y₂) . .. (x_(n),y_(n)) respectively, taking the vertex coordinates of thesecond convex polygon as the virtual primary-color chromaticitycoordinates of the color control system, and taking one of thecoordinate points in the second convex polygon as the virtual whitepoint chromaticity coordinate (x_(w),y_(w)). The number n of primarycolors required to be virtual is a controlled variable number of lightsources. The vertices of the second convex polygon can be freelyselected as desired so long as the vertices are within the common colorgamut. A color range of the corrected colors is the range of the secondconvex polygon. A larger area of the second convex polygon results in awider color display range of light sources. Therefore, a second convexpolygon with a number n as the number of edges is generally made aslarge as possible within the common color gamut.

In a preferred embodiment of the present invention, step S13 comprisesthe following steps:

S13-1: calculating a primary-color tristimulus value

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$and a white-point tristimulus value

$\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$that correspond to the virtual primary-color chromaticity coordinates(x₁,y₁), (x₂,y₂) . . . (x_(n),y_(n)) and the virtual white pointchromaticity coordinate (x_(w),y_(w)) respectively when the brightnessis maximum in step S12, a brightness value at this time is 1, i.e., thevalues of Y₁, Y₂, . . . Y_(n) and Y_(w) are all 1; and

S13-2: calculating tristimulus values corresponding to each primarycolor unit using Grassmann's Law based on the primary-color tristimulusvalue

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$and the white-point tristimulus value

$\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$in step S13-1, a tristimulus value corresponding to each primary colorunit is a color conversion matrix

${\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}},$thereby solving values of the color conversion matrix

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}$and converting the target color parameter to the target colorchromaticity coordinate (x_(t),y_(t)) using the color conversion matrix

${\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}.}$

In a preferred embodiment of the present invention, step S13-1 comprisesthe steps of:

calculating a primary-color tristimulus value

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$and a white-point tristimulus value

$\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$that correspond to the virtual primary-color chromaticity coordinates(x₁,y₁), (x₂,y₂) . . . (x_(n),y_(n)) and the virtual white pointchromaticity coordinate (x_(w),y_(w)) respectively when the brightnessis maximum and a Y value of the tristimulus value is 1 according to aconversion formula

$\left\{ \begin{matrix}{X = \frac{x}{y}} \\{Z = \frac{1 - x - y}{y}}\end{matrix} \right.$between a chromaticity coordinate value and a tristimulus value, inwhich, the values of Y₁, Y₂, . . . Y_(n) and Y_(w) are all 1; and

obtaining a conversion formula

$\left\{ \begin{matrix}{X = \frac{x}{y}} \\{Z = \frac{1 - x - y}{y}}\end{matrix} \right.$between a chromaticity coordinate value and a tristimulus value byconversion when the Y value is 1 due to that the conversion formulabetween a tristimulus value and a chromaticity coordinate value is knownas

$\left\{ \begin{matrix}{x = \frac{X}{X + Y + Z}} \\{y = \frac{Y}{X❘{Y❘Z}}}\end{matrix} \right.$by those skilled in the art, and substituting the virtual primary-colorchromaticity coordinates (x₁,y₁), (x₂,y₂) . . . (x_(n),y_(n)) and thevirtual white point chromaticity coordinate (x_(w),y_(w)) into thisconversion formula to obtain corresponding primary-color tristimulusvalue

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$and white-point tristimulus value

$\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$when the brightness is maximum, in which, for ease of description, the Yvalue is still represented by a character without being converted to avalue 1.

In a preferred embodiment of the present invention, step S13-2 comprisesthe steps of:

S13-2-1: setting duty ratios of each of the primary colors in a mixedcolor of the color control system respectively as P₁, P₂ . . . P_(n), inwhich 0≤P₁, P₂ . . . P_(n)≤1, the color may be any color located withinthe common color gamut, and a tristimulus value of the mixed coloraccording to Grassmann's Law is

$\begin{matrix}{{\begin{bmatrix}X \\Y \\Z\end{bmatrix} = {\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix} \cdot \begin{bmatrix}P_{1} \\P_{2} \\ \vdots \\P_{n}\end{bmatrix}}},} & \end{matrix}$i.e., the tristimulus value

$\begin{bmatrix}X \\Y \\Z\end{bmatrix}$of the mixed color equals to a product of the tristimulus value

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}$corresponding to each primary color unit and duty ratios P₁, P₂ . . .P_(n) of each of the primary colors in the mixed color;

S13-2-2: setting a linear coefficient between the tristimulus value

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}$for each primary color unit and the tristimulus value

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$of the virtual primary-color chromaticity coordinates (x₁,y₁), (x₂,y₂) .. . (x_(n),y_(n)) when the brightness is maximum as

$\begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}$since tristimulus values change linearly, then the tristimulus value foreach primary color unit becomes

$\begin{matrix}{\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix} = {\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}{{{\cdot \begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}};}}}} & \end{matrix}$combining Formula {circle around (1)} and Formula {circle around (2)} toobtain the tristimulus value of the mixed

$\begin{bmatrix}X \\Y \\Z\end{bmatrix} = {\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}{{{\cdot \begin{bmatrix}P \\P_{2} \\ \vdots \\P_{n}\end{bmatrix} \cdot \begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}};}}}$

S13-2-3: the white point tristimulus value, corresponding to the virtualwhite point chromaticity coordinate (x_(w),y_(w)) when the brightness ismaximum, is known as

$\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}{,}$since a primary-color duty ratio when the brightness is maximum is

${\begin{bmatrix}P_{1} \\P_{2} \\ \vdots \\P_{n}\end{bmatrix} = \begin{bmatrix}1 \\1 \\ \vdots \\1\end{bmatrix}},$then

$\begin{matrix}{{{\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix} - {\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix} \cdot \begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}}},{and}}{{\begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix} - {\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1} \cdot \begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}}},}} & \end{matrix}$in which

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1}$is an inverse matrix of

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix};$and

S13-2-4: substituting values of the linear coefficient

$\begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}$calculated in Equation {circle around (3)} into Equation {circle around(2)} to obtain the values of the color conversion matrix

${\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}{as}}{{\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix} \cdot \begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1} \cdot \begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}},}$in which

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$is the primary-color tristimulus value corresponding to the virtualprimary-color chromaticity coordinates (x₁,y₁), (x₂,y₂) . . .(x_(n),y_(n)) when the brightness is maximum,

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1}$is the inverse matrix of

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix},\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$is the white point tristimulus value corresponding to the virtual whitepoint chromaticity coordinate (x_(w),y_(w)) when the brightness ismaximum, and sequential calculations can result in the values of thecolor conversion matrix

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}{,}$i.e., the tristimulus values corresponding to each of the primary colorunits.

It should be noted that

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}{{and}\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}}^{- 1}$in array operations cannot be simplified and combined, both of which arenot reciprocal to each other, as will be appreciated by those skilled inthe art. For solving the inverse matrix

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1},$only when n=3, the equation to be solved has a unique solution, i.e., aunique inverse matrix

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1},$and when n>3, the solution to be solved has a plurality of solutions.According to the solution of the present invention, let

$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1}$be a generalized inverse matrix. Since the specific solution of thegeneralized inverse matrix is well known by those skilled in the art,details are not repeated in the present application.

In a preferred embodiment of the present invention, step S2 comprisesthe following steps:

S21: calculating a tristimulus value

$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix}$of the target color by the color control system using the colorconversion matrix according to the input target color parameter.Specifically, when the input target color parameter is an RGB colorvalue, the color control system firstly converts the target colorparameter to the target color primary-color duty ratio within themulti-color light, and then uses a product of the color conversionmatrix and the target color primary-color duty ratio to obtain thetarget color tristimulus value

$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix}.$In the present embodiment, when the color control system is set, thecolor conversion matrix

$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix} = {{\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix} \cdot \begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1} \cdot \begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}}}$has been solved in step S13-2-4.

S22: converting the target color tristimulus value

$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix}$by the color control system to the target color chromaticity coordinate(x_(t),y_(t)) according to the conversion formula

$\left\{ {\begin{matrix}{x = \frac{X}{X + Y + Z}} \\{y = \frac{Y}{X + Y + Z}}\end{matrix}} \right.$between a chromaticity coordinate value and a tristimulus value, inwhich (x,y) represents the chromaticity coordinate, and

$\begin{bmatrix}X \\Y \\Z\end{bmatrix}$represents the tristimulus value.

The target color parameter is firstly converted to the target colortristimulus value

$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix},$which facilitates converting the target color tristimulus value

$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix}$to the target color chromaticity coordinate value (x_(t),y_(t))according to the conversion formula between the tristimulus value andthe chromaticity coordinate value, thereby ultimately converting thetarget color chromaticity coordinate value by the color implementationsystem to the primary-color duty ratio D_(i) of corrected colors.

In a preferred embodiment of the present invention, setting colorimplementation in step S1 comprises the steps of: measuring thechromaticity coordinate values (x_(i),y_(i)) and a maximum brightnessvalue Y_(i) of each of the primary colors of different light sourcesunder a maximum duty ratio, in which i represents an i-th primary color,and storing measurement values into corresponding lights.

In a process of setting the color control system, it is desirable tomeasure respective color gamuts of different light sources and recordinto a chromaticity diagram to form a plurality of first convexpolygons, the vertex coordinates of each of the first convex polygonsare the chromaticity coordinate values (x_(i),y_(i)) of each of theprimary colors of the corresponding light source under a maximum dutyratio, and the chromaticity coordinates can be directly measured by anintegrating sphere. When measured, only one of the primary colors of thelight source is turned on while other primary colors of the light sourceare turned off, the illuminated primary color is under the maximum dutyratio (the duty cycle at this time is generally considered to be 1), andthen the chromaticity coordinate value (x_(i),y_(i)) and the brightnessvalue Y_(i) are measured.

Optionally, similar to measuring respective color gamuts of differentlight sources, both the chromaticity coordinate values (x_(i),y_(i)) anda maximum brightness value Y_(i) of each of the primary colors ofdifferent light sources under a maximum duty ratio are measured one byone, model by model, or batch by batch, both of which are measured inthe same manner.

Optionally, there may be one light source or a plurality of lightsources within each multi-color light, and when there are a plurality oflight sources within one multi-color light, similar to measuringrespective color gamuts of different light sources, each one/eachmodel/each batch of light sources needs to be corrected, both of whichare measured in the same manner to unify light emission colors of theplurality of light sources within the same multi-color light.

Preferably, in the present embodiment, there is only one light source,or two and more light sources of the same model inside the multi-colorlight.

In a preferred embodiment of the present invention, step S3 comprisesthe steps of:

substituting the target color chromaticity coordinate value(x_(t),y_(t)) and the chromaticity coordinate value (x_(i),y_(i)) andthe maximum brightness value Y_(i) of each of the primary colors ofcorresponding light sources under a maximum duty ratio into a conversionformula between a tristimulus value and a chromaticity coordinate valueto

obtain

${x_{t} = {\frac{X_{t}}{X_{t} + Y_{t} + Z_{t}} = {\frac{\sum\limits_{i = 1}^{n}{\left\lbrack {x_{t}*\left( {X_{t} + Y_{t} + Z_{t}} \right)} \right\rbrack*D_{i}}}{\sum\limits_{i = 1}^{n}{\left( {X_{t} + Y_{t} + Z_{t}} \right)*D_{i}}} = {\frac{\sum\limits_{i = 1}^{n}{\frac{x_{t}*Y_{t}}{y_{i}}*D_{i}}}{\sum\limits_{i = 1}^{n}{\frac{Y_{t}}{y_{i}}*D_{i}}}{and}}}}}{{y_{t} = {\frac{Y_{t}}{X_{t} + Y_{t} + Z_{t}} = {\frac{\sum\limits_{i = 1}^{n}{\left\lbrack {y_{t}*\left( {X_{t} + Y_{t} + Z_{t}} \right)} \right\rbrack*D_{i}}}{\sum\limits_{i = 1}^{n}{\left( {X_{t} + Y_{t} + Z_{t}} \right)*D_{i}}} = \frac{\sum\limits_{i = 1}^{n}{\frac{y_{t}*Y_{t}}{y_{i}}*D_{i}}}{\sum\limits_{i = 1}^{n}{\frac{Y_{t}}{y_{i}}*D_{i}}}}}},}$and obtain the following after simplification:

$\begin{matrix}{{{\sum\limits_{i = 1}^{n}{\frac{Y_{t}*\left( {x_{t} - x_{i}} \right)}{y_{i}}*D_{i}}} = 0};} & \end{matrix}$ $\begin{matrix}{{{\sum\limits_{i = 1}^{n}{\frac{Y_{t}*\left( {y_{t} - y_{i}} \right)}{y_{i}}*D_{i}}} = 0};} & \end{matrix}$in which 0≤D_(i)≤1, n is the number of primary colors, i represents ani-th primary color, and the primary-color duty ratio D_(i) of correctedcolors is solved using linear programming in combination with Equation{circle around (4)} and Equation {circle around (5)}.

In a preferred embodiment of the present invention, an objectivefunction is set as maximized target color brightness, then max Z=Σ_(i=1)^(n)Y_(i)*D_(i) {circle around (6)}, in which max Z represents themaximum brightness, Equation {circle around (4)}, Equation {circlearound (5)} and Equation {circle around (6)} are solved using linearprogramming to obtain the primary-color duty ratio D_(i) of correctedcolors.

Obviously, the above embodiments of the present invention are merelyexamples for clear illustration of the technical solutions of thepresent invention, and are not intended to limit the implementation ofthe present invention. Any modification, equivalent substitution,improvement or the like within the spirit and principle of claims of thepresent invention should be included in the scope of the claims of thepresent invention.

The invention claimed is:
 1. A unified color control method for amulti-color light, comprising the following control steps: S1: settingunified color control system and color implementation system fordifferent light sources; S2: inputting a target color parameter, andcalculating a target color chromaticity coordinate (x_(t),y_(t)) by thecolor control system according to the target color parameter; S3:calculating a primary-color duty ratio D_(i) of corrected colors by thecolor implementation system using a linear programming equationaccording to the target color chromaticity coordinate (x_(t),y_(t)), anda chromaticity coordinate value (x_(i),y_(i)) and a maximum brightnessvalue Y_(i) of each primary color for each light source under a maximumduty ratio, wherein i represents an i-th primary color; and S4: updatingcolors by the light sources according to the primary-color duty ratioD_(i) of the corrected colors in step S3.
 2. The unified color controlmethod for the multi-color light according to claim 1, wherein setting acolor control system in step S1 comprises the following steps: S11:measuring respective color gamuts of different light sources to obtain acommon color gamut; S12: selecting virtual primary-color chromaticitycoordinates (x₁,y_(i)), (x₂,y₂) . . . (x_(n),y_(n)) and a virtual whitepoint chromaticity coordinate (x_(w),y_(w)) of the color control systemwithin the common color gamut; and S13: calculating a color conversionmatrix $\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}$ for converting the target color parameter to the targetcolor chromaticity coordinate (x_(t),y_(t)) according to the virtualprimary-color chromaticity coordinates (x₁,y₁), (x₂,y₂) . . .(x_(n),y_(n)) and the virtual white point chromaticity coordinate(x_(w),y_(w)).
 3. The unified color control method for the multi-colorlight according to claim 2, wherein step S11 comprises the steps of:measuring respective color gamuts of different light sources andrecording into a chromaticity diagram to form a plurality of firstconvex polygons, wherein an intersection of all the first convexpolygons is the common color gamut.
 4. The unified color control methodfor a multi-color light according to claim 2, wherein step S12 comprisesthe steps of: making a second convex polygon with a number n as thenumber of edges within the common color gamut according to the number nof primary colors required to be virtual, in which n is no less than 3;and setting vertex coordinates of the second convex polygon as (x₁,y₁),(x₂,y₂) . . . (x_(n),y_(n)) respectively, taking the vertex coordinatesof the second convex polygon as the virtual primary-color chromaticitycoordinates of the color control system, and taking one of thecoordinate points in the second convex polygon as the virtual whitepoint chromaticity coordinate (x_(w),y_(w)).
 5. The unified colorcontrol method for the multi-color light according to claim 2, whereinstep S13 comprises the following steps: S13-1: calculating aprimary-color tristimulus value $\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$ and a white-point tristimulus value $\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$ that correspond to the virtual primary-colorchromaticity coordinates (x₁,y₁), (x₂,y₂) . . . (x_(n),y_(n)) and thevirtual white point chromaticity coordinate (x_(w),y_(w)) respectivelywhen the brightness is maximum in step S12; and S13-2: calculatingtristimulus values, i.e., the color conversion matrix $\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}{,}$ corresponding to each of the primary color unitsusing Grassmann's Law based on the primary-color tristimulus value$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$ and the white-point tristimulus value $\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$ in step S13-1.
 6. The unified color control method forthe multi-color light according to claim 5, wherein step S13-1 isspecifically as follows: calculating a primary-color tristimulus value$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$ and a white-point tristimulus value $\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}$ that correspond to the virtual primary-colorchromaticity coordinates (x₁,y₁), (x₂,y₂) . . . (x_(n),y_(n)) and thevirtual white point chromaticity coordinate (x_(w),y_(w)) respectivelywhen the brightness is maximum and a Y value of the tristimulus value is1 according to a conversion formula $\left\{ {\begin{matrix}{X = \frac{x}{y}} \\{Z = \frac{1 - x - y}{y}}\end{matrix}} \right.$ between a chromaticity coordinate value and atristimulus value, wherein, the values of Y₁, Y₂ . . . Y_(n) and Y_(w)are all
 1. 7. The unified color control method for the multi-color lightaccording to claim 5, wherein step S13-2 comprises the steps of:S13-2-1: setting duty ratios of each of the primary colors in a mixedcolor of the color control system respectively as P₁, P₂ . . . P_(n),0≤P₁, P₂ . . . P_(n)≤1, and a tristimulus value of the mixed coloraccording to Grassmann's Law is $\begin{matrix}{{\begin{bmatrix}X \\Y \\Z\end{bmatrix} = {\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix} \cdot \begin{bmatrix}P_{1} \\P_{2} \\ \vdots \\P_{n}\end{bmatrix}}};} & \end{matrix}$ S13-2-2: setting a linear coefficient between thetristimulus value $\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}$ for each primary color unit and the tristimulus value$\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}$ of the virtual primary-color chromaticity coordinates(x₁,y₁), (x₂,y₂) . . . (x_(n),y_(n)) when the brightness is maximum as$\begin{matrix}{\begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix},{{{{then}\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}} = {\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix} \cdot \begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}}};}} & \end{matrix}$ and combining Formula {circle around (1)} and Formula{circle around (2)} to obtain ${\begin{bmatrix}X \\Y \\Z\end{bmatrix} = {\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix} \cdot \begin{bmatrix}P_{1} \\P_{2} \\ \vdots \\P_{n}\end{bmatrix} \cdot \begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}}};$ S13-2-3: the white point tristimulus value,corresponding to the virtual white point chromaticity coordinate(x_(w),y_(w)) when the brightness is maximum, is known as$\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix},$ since the primary-color duty ratio at this time is${\begin{bmatrix}P_{1} \\P_{2} \\ \vdots \\P_{n}\end{bmatrix} = \begin{bmatrix}1 \\1 \\ \vdots \\1\end{bmatrix}},$ then $\begin{matrix}{{{\begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix} = {\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix} \cdot \begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}}},{and}}{{\begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix} = {\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1} \cdot \begin{bmatrix}X_{w} \\Y_{w} \\Z_{w}\end{bmatrix}}},}} & \end{matrix}$ wherein $\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix}^{- 1}$ is an inverse matrix of $\begin{bmatrix}X_{1} & X_{2} & & X_{n} \\Y_{1} & Y_{2} & \ldots & Y_{n} \\Z_{1} & Z_{2} & & Z_{n}\end{bmatrix};$ and S13-2-4: substituting values of the linearcoefficient $\begin{bmatrix}K_{1} \\K_{2} \\ \vdots \\K_{n}\end{bmatrix}$ calculated in Equation {circle around (3)} into Equation{circle around (2)} to obtain the values of the color conversion matrix$\begin{bmatrix}\left( X_{1} \right) & \left( X_{2} \right) & & \left( X_{n} \right) \\\left( Y_{1} \right) & \left( Y_{2} \right) & \ldots & \left( Y_{n} \right) \\\left( Z_{1} \right) & \left( Z_{2} \right) & & \left( Z_{n} \right)\end{bmatrix}.$
 8. The unified color control method for the multi-colorlight according to claim 1, wherein step S2 comprises the followingsteps: S21: calculating a tristimulus value $\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix}$ of the target color by the color control system usingthe color conversion matrix according to the input target colorparameter; and S22: converting the target color tristimulus value$\begin{bmatrix}X_{t} \\Y_{t} \\Z_{t}\end{bmatrix}$ by the color control system to the target colorchromaticity coordinate (x_(t),y_(t)) according to the conversionformula $\left\{ {\begin{matrix}{x = \frac{X}{X + Y + Z}} \\{y = \frac{Y}{X + Y + Z}}\end{matrix}} \right.$ between a chromaticity coordinate value and atristimulus value, wherein (x,y) represents the chromaticity coordinate,and $\begin{bmatrix}X \\Y \\Z\end{bmatrix}$ represents the tristimulus value.
 9. The unified colorcontrol method for the multi-color light according to claim 1, whereinsetting color implementation in step S comprises: measuring thechromaticity coordinate values (x_(i),y_(i)) and a maximum brightnessvalue Y_(i) of each of the primary colors of different light sourcesunder a maximum duty ratio, wherein i represents an i-th primary color,and storing measurement values into corresponding lights.
 10. Theunified color control method for the multi-color light according toclaim 1, wherein step S3 is specifically as follows: substituting thetarget color chromaticity coordinate value (x_(t),y_(t)) and thechromaticity coordinate value (x_(i),y_(i)) and the maximum brightnessvalue Y_(i) of each of the primary colors of corresponding light sourcesunder a maximum duty ratio into a conversion formula between atristimulus value and a chromaticity coordinate value to obtain$\begin{matrix}{{{{\sum}_{i = 1}^{n}\frac{Y_{i}*\left( {x_{t} - y_{i}} \right)}{y_{i}}*D_{i}} = 0};} & \end{matrix}$ $\begin{matrix}{{{{\sum}_{i = 1}^{n}\frac{Y_{i}*\left( {y_{t} - y_{i}} \right)}{y_{i}}*D_{i}} = 0};} & \end{matrix}$ wherein 0≤D_(i)≤1, n is the number of primary colors, irepresents an i-th primary color, and the primary-color duty ratio D_(i)of corrected colors is solved using linear programming in combinationwith Equation {circle around (4)} and Equation {circle around (5)}. 11.The unified color control method for the multi-color light according toclaim 10, wherein setting an objective function as maximized targetcolor brightness, max Z=Σ_(i=1) ^(n)Y_(i)*D_(i) {circle around (6)};wherein max Z represents the maximum brightness, Equation {circle around(4)}, Equation {circle around (5)} and Equation {circle around (6)} aresolved using linear programming to obtain the primary-color duty ratioD_(i) of the corrected colors.